rand - generate pseudo-random bytes
openssl rand [-out file] [-rand file(s)] [-base64] num
The rand command outputs num pseudo-random bytes after seeding the random number generator once. As in other openssl command line tools, PRNG seeding uses the file $HOME/.rnd or .rnd in addition to the files given in the -rand option. A new $HOME/.rnd or .rnd file will be written back if enough seeding was obtained from these sources.
-out file Write to file instead of standard output. -rand file(s) Use specified file or files or EGD socket (see RAND_egd(3)) for seeding the random number generator. Multiple files can be specified separated by a OS-dependent character. The separator is ; for MS-Windows, , for OpenVMS, and : for all others. -base64 Perform base64 encoding on the output.